In vitro culturing of cells has been a useful research tool, providing material necessary for research in pharmacology, physiology and toxicology. Recent advances in the field of developmental biology, significantly in the isolation, growth and differentiation of stem cells, have opened the door for cell culture to provide material for therapeutic applications as well. Embryonic stem cells, including human embryonic stem cells, may be able to provide answers to difficult medical problems such as Alzheimer's disease, Parkinson's disease, diabetes, spinal cord injury, heart disease, and other debilitating and often fatal conditions.
Embryonic stem cells represent an example of difficult-to-culture cell types. Embryonic stem cells are particularly difficult to culture, difficult to control, and often require a specialized cell culture surface that can facilitate growth and proliferation of these cells in their undifferentiated state. Many coatings and surface enhancements have been developed to provide cell culture surfaces which promote cell growth in vitro. Some of these coatings and surface enhancements provide surfaces that support the culture of difficult-to-culture cells such as embryonic stem cells. However, many of these surfaces contain animal-derived additives such as proteins or cell extracts. These additives introduce a risk of infection into the preparation of therapeutic cells. For example, the use of extra-cellular matrix proteins derived from animals may introduce infective agents such as viruses or prions. These infective agents may be taken up by cells in culture and, upon the transplantation of these cells into a patient, may be taken up into the patient. Therefore, the addition of these factors in or on cell culture surfaces may introduce new disease even as they address an existing condition. In addition, these animal-derived additives or cell surface coatings may lead to significant manufacturing expense and lot-to-lot variability which are not preferable. There is a need for cell culture surfaces which do not include animal-derived ingredients or additives and which provide cell culture conditions amenable for cell culture, including the culture of difficult-to-culture cells such as embryonic stem cells.